In producing a three dimensional object, such as a polyhedron where it is desirable to provide patterns on different surfaces for photoresponsive operations, it would be of advantage to produce a pattern on each surface without having to reposition the object. A particular illustration is in the field of solid state electronic apparatus where the wiring, for a plurality of integrated circuit members that have been assembled into a stack having an overall polyhedron shape, is formed on the surfaces of the polyhedron. The standard way in the art of forming such wiring is by the separate projection or contact printing, for subsequent photolithographic conductor formation of an image of the wiring for each individual surface, on that respective surface. Where there is a high conductor density and interrelationship of conductor patterns from surface to surface, the problems of the positioning in registration of the surfaces of the polyhedron shaped integrated circuit stack for separate photolithographic conductor formation on each surface requires meticulous attention and adds to cost in manufacturing.
There has been some activity in the electronic apparatus field photolithographic accommodation of three dimensional features and consideration.
In U.S. Pat. No. 5,001,038, in the printed circuit manufacturing field, differences in surface level are accommodated by using different masks for different levels relative to a reference plane.
In Japanese Patent document 3 183115 A the considerations of flaws in mask patterns in the semiconductor manufacturing field is accommodated by superimposing more than one mask in an optical path to be projected onto a substrate. It would be of advantage to be able to project an image on each surface of a three dimensional object simultaneously and without having to reposition the object.